How can I kill Evil Marie or Krampus on one life?

This can help you.

BOSS #3 – EVIL MARIE

Location: End of Haunted House Description: Aristocratic ghost with a bloody neck Difficulty: Hard Death sequence: Blasted out of the air and is impaled on a pointy monument. I think she says something, but I’m not sure what it is….if anyone knows, please email me.

Evil Marie is HHHHAAARRRDDDD. In fact, she’s probably the second toughest boss after the Baron himself. Her weak spot is the scar on her neck, but this is very hard to hit while she’s mercilessly swinging her axe at you. Hit her two or three times and she’ll fly ahead and fly back and forth while throwing axes at you. Don’t bother trying to hit her, just blast those axes! She’ll use these two patterns for a while, and when you wear enough health off, her defense weakens and you can hit her anywhere.

After she’s fluctuated between these two patterns and her health is down to about an inch, she’s hover in the air charging up energy blasts. Shoot her as fast as you can (you can hit her anywhere now) because you can’t stop the blasts. She’ll probably get one off, but you should be able to destroy her before she does another one.

BOSS #4 – KRAMPUS

Location: End of Rickety Town Description: Green-suited Santa Claus with talons and antlers Difficulty: Hard Death sequence: Stumbles backwards saying “Oh no, oh no, oh no!” and collapses.

Krampus is pretty tough. His slashing combos are pretty much impossible to avoid getting hit by, so just try to bloody all of his parts-especially his chest, since you can expose his heart, a major weak point.

Krampus has three main attacks. Slashing with his claws, swinging his bag and throwing hot coals out of his bag. His coals can be shot, his bag can be deflected if you shoot it enough, but I don’t think his slashes can be avoided. Just aim for the bag when he says “Let’s see what I got for YOU!” and be ready to shoot projectiles when he says “How about a nice lump of coal!”

source: https://gamefaqs.gamespot.com/arcade/574651-carnevil/faqs/8877

Try asking the arcade manager if he can turn the monster strength and or the player health to very easy in the dip switch menu. If you are doing it on mame, then hit F2. If you want to you can also ask the arcade manager to set the junior boss to deaddy a monster teddy bear. Of course if you really want to, if you have mame, you can set cheats, but I wouldn't recommend it. Also you could also ak the arcade manager to turn down game difficulty, but that would just limit the enemies. Also if you want, you can have 2 players one player shoots all the enemies, the other holds the powerups, (mainly the acid bath for krampus).

Having just achieved the world record, I can confirm all the bosses are killable in one credit.

http://www.aurcade.com/members/submission.aspx?id=169142

Krampus: I aimed for the upper chest, just below his chin. That guaranteed a reasonably equal shot placement between his head, chest, and arms. Bloodying each of those areas causes him to stagger, which buys you valuable time to get additional hits in. Shooting the legs staggers him for a little longer but I personally had a lot of trouble getting enough focused shots in to get them bloodied during the heat of the fight. He doesn't take damage while he's skating, but he does take hits on the throne for a second before the fight starts. If you shoot fast enough, you can even stagger him before he jumps down to attack.

Also, the initial question was incorrect: you can't get to Krampus with full health. Since you're required to take half a bar of damage from behind at the garage shortly before the fight that means you have to fight with half a bar of health at most.

Evil Marie: She's harder than Krampus because she lacks the big beefy hit areas, but since you're not required to take a serious amount of hits in her stage and there are three health pickups as opposed to Rickety Town's one you can enter her arena with way more health so it ends up being a lot easier to deal with her.

Just start the fight shooting as quickly as possible into her chest, after enough shots she staggers a little bit. I found you get a good bit of extra damage by going easy on her in the beginning section of the fight and just shooting her until the bar drops to the beginning of the last 'E' in her name, letting her fly into the air for the axe throwing section, and then shooting her extra while she's on her way up into the air and during her teleportation back onto the ground. If you shoot too fast in the beginning she skips flying up to throw the axes and you have less time to do the required damage. Unlike Krampus, she has no invincibility during movement so you can do a ton of damage by shooting her while she's on the bridge. She technically has a secondary axe throwing stage on the bridge but I always out-damaged her and forced her into the energy ball throwing section.

At the end of the day, the solution to CarnEvil really is just to up your shorts-per-second enough to out-damage the bosses. I ended up bracing the gun against my chest, pumping with my left hand, and feathering the trigger with my right hand while shifting my chest to aim broadly at different sections of the screen.